GL: Bottom paint advice

[John & Judy Gill]

Tommy and list,

Please read my post again.  I did not say that all boats are going to  
blister!  What I said was that it is a good idea to start with a  
barrier coat before putting on an ablative bottom paint.  There are  
two boats in my marina that are less than two years old which have  
blistered so badly that they had to have the entire bottom (gel coat)  
removed down to the fiberglas roving and then redone - this time with  
an epoxy barrier coat.  The manufacturer only paid about half the  
bill for the repairs.

If one wants to wait until blisters appear and then either face the  
problem every year with new blisters or have to have the whole bottom  
done, that is their choice, but it will be more expensive to sand  
blast or remove all the bottom paint in order to then have a barrier  
coat put on.

John Gill

P.S.  The writer retired from Rohm and Haas Company who manufacturers  
acrylic polymers for the paint industry and for fiberglas gel coat  
systems.  RandH invented acrylic (Plexiglas) in 1901 and has been the  
world leader in acrylic technology ever since.  The company also  
manufacturers the microbicide used in commercial ship paints.

===================================
On Nov 3, 2006, at 11:57 AM, Tommy Terrific wrote:

>  That is a mighty expensive decision/ 
> assumption.................that all boats are going to blister,  
> therefore we should put a barrier coat on all boats.
>
>  Actually, very few boats blister now.
>
>  Tommy
>
>
>  ----- Original Message -----  From: "John & Judy Gill"  
> <twojscom@quadnet.net>
>  To: "Greg Schoenberg" <dene@ipns.com>
>  Cc: "Loop" <great-loop@lists.samurai.com>
>  Sent: Friday, November 03, 2006 11:27 AM
>  Subject: Re: GL: Bottom paint advice
>
>
>  >I hate to disagree with Tommy, but barrier coats (two part epoxy) is
>  > a very good idea on brand new boats to prevent gel coat blistering.
>  > It is also a good idea to apply a barrier coat on a boat which has
>  > started to blister (after all blisters have been properly dug  
> out and
>  > dried)  -  you do not have to remove the entire gel coat to apply a
>  > barrier coat.  The problem started when boat manufacturers switched
>  > from all acrylic gel coat systems to co-polymers of styrene and
>  > acrylic to save money.  Note that all bottom paint must be removed
>  > and the surface roughed up to provide goo adhesion of the epoxy
>  > barrier coat.
>  >
>  > John Gill
>  > AGLCA Looper
>  >
>  > ====================================